Analysis of the IH 35 Corridor Through the Austin Metropolitan Area

TRB Planning Applications Conference

Jeff SheltonKaren Lorenzini

Alex ValdezTom Williams

May 8, 2013

Acknowledgements

• University of Arizona• RST International• TxDOT• CAMPO• CTRMA• Capital Metro• City of Austin• Downtown Austin Alliance

Introduction

• Austin among the fastest-growing cities in the U.S.• Average travel times from downtown to Round Rock (45 – 60 mins) during afternoon peak

Introduction

• Funding only available for incremental improvements

• Need to start planning for the “Big Picture”

Introduction

What is the long-term solution for IH 35 through the

Austin Metropolitan Area?

Introduction

• Pre-conceptual, unbounded by financial constraints

• Framework for preliminary screening of options

• Advanced research tool for advanced research challenge

• Use different resolution levels to meet challenge (TDM DTA)

Public Notions about IH 35

• Through (bypass) traffic causing congestion• Truck traffic major problem• We can build our way out of congestion

Technical Approach – Demand Side

• Analysis year 2035 for all scenarios• Travel demand model starting point: CAMPO

regional travel demand model • Multiple vehicle class trip tables• SOV, HOV2/HOV3+, Truck

• All other 2035 adopted plan roads and transit network included

Technical Approach – Demand Side

• Scenario 0 (Base model)

• Concurrent with CAMPO adopted plan

• No additional vehicle capacity along IH 35 between SH 45 North and SH 45 South

Technical Approach – Supply Side

• Dynamic traffic assignment (DynusT) • Assignment is modeled in 1-minute

intervals• Traffic signals coded on all major arterials• Innovative congestive-responsive tolling

algorithm

Congestive Responsive Tolling

Congestive Responsive Tolling

Congestive Responsive Tolling

Maximize throughput while maintaining target speed

Challenges

• Network size• Run time• Signal timings• Multiple vehicle classes• Dynamic tolling algorithm• Outputs

Concept Scenarios

Base Model

• Concurrent with the current CAMPO adopted plan

• No additional vehicle capacity along IH 35 between SH 45 North and SH 45 South

• All other 2035 CAMPO Adopted Plan Roads and Transit Network included

HOV laneStatic tollDynamic toll

Scenario 1

• One express lane added each direction to IH 35, non-tolled

• SOV and trucks restricted• Dynamic tolling MoPac and

SH 183• Toll for HOV3+

HOV laneStatic tollDynamic toll

Scenario 2

• Dynamic pricing IH 35• Min toll ($0.25)• Max toll ($200.00)• HOV 3+ free

• Independent tolling scheme on other facilities

HOV laneStatic tollDynamic toll

Scenario 3

• System-wide dynamic pricing • IH 35• HOV 3+ free

• All other facilities, HOV pays

HOV laneStatic tollDynamic toll

Scenario 4

• Dynamic pricing IH 35• Add one additional

express lane each direction

• Remove one general purpose lane each direction

• Remove tolls SH 130/45 and redesignate as interstateHOV lane

Static tollDynamic toll

Scenario 5

• No added capacity• Toll existing IH 35 main

lanes• Peak period dynamic

pricing • 6-9 AM• 4-7 PM

• Remove tolls SH 130/45 and redesignate as interstateHOV lane

Static tollDynamic toll

Scenario 6

• Three additional express lanes in each direction

• Elevated or depressed• Access only at endpoints• Dynamically tolled• HOV3+ free• SOV min toll ($9.94)• Truck min toll ($31.58)

HOV laneStatic tollDynamic toll

What did we find out?

Base Scenario

Scenario 1

Scenario 2

Scenario 3

Scenario 4

Scenario 5

Scenario 6

Results

31

Base 1 2 3 4 5 6

Base SC1 SCS2 SC3 SC4 SC5 SC62,400,000

2,450,000

2,500,000

2,550,000

2,600,000

2,650,000VHT - Internal Trips

VHT

(hrs

)

Base SC1 SCS2 SC3 SC4 SC5 SC614,000

14,500

15,000

15,500

16,000

16,500

17,000

17,500

18,000

18,500

19,000VHT - External Trips

VHT

(hrs

)

Shortest Path?Base Scenario Scenario 5

Majority of truck traffic already using SH 130 to bypass central downtown core

What did we learn?

• Recurring congestion caused by daily commuters – NOT through traffic

• Removing truck traffic from IH 35 fills with latent demand

• Added pavement (highest $) did not show promising results

• Biggest problem is growth trends and “business as usual” travel behavior

People Make More Trips Outside of Peak Period

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 240

200,000

400,000

600,000

800,000

1,000,000

1,200,000

TOTAL HOURLY TRIPS

2015 2035: Scenario 0 Base

What would it take?

• From CAMPO 2035 plan• Two express lanes in each direction – One of these lanes is on-going

express lane implementation project

– Length from SH 45N to SH 45 SE

– Intermediate access points– SOV/HOV pay an auto toll

rate, transit free– Dynamically tolled

Travel Behavior Changes Trip reduction per household Travelers shorten travel

distances somewhat Peaks spread into non-peak

periods HOV3 , Transit, and non-

motorized travel increases 125%

Added Capacity High Efficient Land Use

People Make More Trips Outside of Peak Period

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 240

200,000

400,000

600,000

800,000

1,000,000

1,200,000

TOTAL HOURLY TRIPS

2015 2035: Scenario 0 Base What Would It Take?

What would it take?

10 mph

20 mph

30 mph

40 mph

50 mph

60 mph

Riverside

SH 45

US 183

SH 45

Riverside

SH 45

US 183

SH 45

2:00

4:00

6:00

8:00

10:0

0

12:0

0

2:00

4:00

6:00

8:00

10:0

0

2:00

4:00

6:00

8:00

10:0

0

12:0

0

2:00

4:00

6:00

8:00

10:0

0

IH 35 Ext to Ext (Northbound) IH 35 Ext to Ext (Southbound)

Moving Forward

• Educating decision-makers/public about myths • Pursuing demand side strategies– Employers– Individuals– Public policy (including land use)

• Defining specific long-term capacity improvements• Expand modal options/accessibility• Leverage new technologies• Continue to refine model tools

Thank You